The present invention is a device that employs electrical discharges/non-thermal plasmas in a gaseous medium to activate a fuel derived from a fuel injector to promote more effective and efficient combustion. In non-thermal plasmas, the electrons are ‘hot’, while the ions and neutral species are ‘cold’—which results in little waste enthalpy being deposited in a process gas stream. This is in contrast to thermal plasmas, where the electron, ion, and neutral-species energies are in thermal equilibrium (or ‘hot’) and considerable waste heat is deposited in the process gas.
The present invention utilizes a type of electrical discharge called a dielectric barrier discharge (DBD) or silent discharge plasma (SDP) to: 1) break up large organic fuel molecules into smaller ones that are more easily and completely combusted; and 2) create highly reactive free-radical chemical species that can promote more efficient combustion by their strong “redox” power (fuels become strong reducing agents, oxygen becomes more oxidizing) or by their ability to promote combustion-sustaining chain reactions or chain reactions that further generate active species. This device is envisioned for application to a variety of internal combustion engines, such as automobile engines and all turbine engines that normally employ fuel injectors.
U.S. Pat. No. 6,606,855, Plasma Reforming and Partial Oxidation of Hydrocarbon Fuel Vapor to Produce Synthesis Gas And/Or Hydrogen Gas, by Kong et al., teaches methods and systems for treating vapors from fuels with thermal or non-thermal plasmas to promote reforming reactions between the fuel vapor and re-directed exhaust gases to produce carbon monoxide and hydrogen gas, partial oxidation reactions between the fuel vapor and air to produce carbon monoxide and hydrogen gas, or direct hydrogen and carbon particle production from the fuel vapor. However, a problem with the reactions taught in Kong et al. includes the fact that hydrocarbon gases, when formed, are accompanied with carbon particles (ie. Soot). Introduction of carbon particles into a working engine is considered undesirable due to the engine damage that can be caused and, in particular, the difficulty in combusting the carbon particles.
In contrast, the present invention is a specific non-thermal plasma fuel injector, designed to make free radicals and more easily-combusted cracked species of out of injected fuel to enhance combustion with no formation of soot. There are no oxidative reactions as in Kong et al. and only fuel is treated, not O2 or exhaust gases as described in Kong et al.
U.S. Pat. No. 6,322,757, Low Power Compact Plasma Fuel Converter, by Cohn et al., also teaches the conversion of fuel, particularly into molecular hydrogen (H2) and carbon monoxide (CO). The invention of Cohn et al, like Kong et al., suffers from rampant soot production, as well as electrode erosion (because the Plasmatron converter actually employs a hot-arc, thermal plasma, rather than a low-temperature, non-thermal plasma). Further, it is not clearly evident that molecular hydrogen is the key promoter of more stable/complete combustion.
Various objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.